 
 (defn get-or-generate-thumbnail
   [system thumb-map]
+  (assert-original-mime-type (get thumb-map :original) thumb-map)
   (if-let [thumb (and (not (q/query-opt thumb-map :replace))
                       (get-thumbnail (store system) thumb-map))]
     thumb


(defn original->thumbnail
  [resource thumb-map]
  (assert-original-mime-type resource thumb-map)
  (let [temp-file (temp-filename (str (wikia thumb-map) "_thumb"))
        base-command [thumbnail-bin
                      "--in" (.getAbsolutePath resource)

(defn assert-original-mime-type
  [file thumb-map]
  (let [mime-type (mime-type-of file)]
    (when (contains? unsupported-mime-types mime-type)
      (throw+ {:type :convert-error
               :response-code 404
               :content-type mime-type
